1. Technical Field
This invention relates to a golf ball having improved flight performance.
2. Background Art
As is well known in the art, in order to improve the flight performance of a golf ball, that is, in order for a golf ball to travel a distance when launched, the rebound properties of the ball itself dependent on materials used therein and the sophisticated arrangement of dimples on the ball surface to reduce the air resistance of the ball in flight are important. With respect to the dimples, from the standpoint of distributing dimples as uniformly and densely as possible, there have been proposed from the past a number of design solutions to dimple shape, dimple arrangement, dimple volume relative to ball volume and the like. See JP-A 9-122272, for example. With respect to the radial cross-sectional shape of dimples, a number of designs have been proposed including an arcuate shape, a combination of two arcuate shapes, and a pan bottom shape.
As to the golf ball standards, the ball must have a diameter of not less than 42.67 mm and a weight of not greater than 45.93 grams according to the Rules of Golf (USGA). It is thus a common practice for golf ball manufacturers to manufacture golf balls by designing a model having a slightly larger diameter, hence a slightly larger volume and a slightly lower weight to insure some allowances for the prescribed values, so that the balls are not outside the standards.
Under the circumstances, active studies have been made on the materials used, dimple shape, dimple arrangement, dimple volume relative to ball volume and the like, with the target of improving golf ball flight performance. Nevertheless, no concern about the specific gravity of the ball in entirety has arisen from the standpoint of improving golf ball flight performance.